1. Field of the Invention
The present invention relates to a liquid crystal display device and a display device, and more particularly to a liquid crystal display device and a display device that are adaptive for simplifying its manufacturing process and reducing its cost.
2. Discussion of the Related Art
Generally, a liquid crystal display (LCD) device is a representative display of flat panel displays. The LCD displays a picture by controlling an amount of light in correspondence to a video signal. Because it has such advantages as lightness, thinness, low power consumption and so on, the LCD is in a trend to broaden the range of its application. According to this trend, the LCD is widely used as a display device for notebook computers and office automation equipment. Further, the LCD is in a trend toward large-sized screen, high precision and low power consumption.
FIG. 1 illustrates an assembly diagram of a liquid crystal display (LCD) device according to the related art. Referring to FIG. 1, the LCD device includes a liquid crystal display panel 2; a backlight unit to irradiate light to the LCD panel; a support main 16 to house the LCD panel 2 and the backlight unit; a cover bottom 20 combined with one side of the support main 16 to fix the backlight unit and to support the support main 16; a guide panel 4 arranged between the backlight unit and the LCD panel 2 to support the LCD panel 2 and to be combined with the side surfaces of the support main 16; and a case top 6 covering the side walls of the guide panel 4 and the edges of the LCD panel 2.
The LCD panel 2 includes a plurality of liquid crystal cells arranged in a matrix configuration between upper and lower glass substrates and a thin film transistor at each of the liquid crystal cells to switch a video signal. The refractive index of each of the liquid crystal cells changes in accordance with the video signal, thus a picture corresponding to the video signal can be displayed. A tape carrier package (not shown) is attached to the lower substrate of the LCD panel 2, wherein a driver integrated circuit is mounted on the tape carrier package to apply a drive signal to a thin film transistor. Further, polarizing sheets 8 and 18 are attached to the front and rear surfaces of the LCD panel 2. The polarizing sheets 8 and 18 may have an additional function of improving the viewing angle of the LCD device.
The backlight unit includes a lamp 36, which receives electric power from an external power source, to irradiate light to the LCD panel 2; a light guide panel 12 to direct the incident light from a light-incoming part, which is formed at the side surface facing the lamp 36, toward the LCD panel 2; a lamp housing 34 to cover the lamp 36 and the light-incoming part of the light guide panel 12; a reflection sheet 14 arranged at the rear surface of the light guide panel 12; and a plurality of optical sheets 10 to improve the efficiency of the light traveling to the LCD panel 2.
The lamp 36 includes a high voltage electrode and a low voltage electrode which are formed at both ends of a glass tube; a high voltage wire 44 connected to the high voltage electrode by soldering; and a low voltage wire 42 connected to the low voltage electrode. The high and low voltage electrodes soldered with the wires 42 and 44 are covered with an insulating holder. Further, the high and low voltage wires 44 and 42 are connected to outside of the LCD device, for example, to a connector 40 through a wire fixation part 60 formed at the guide panel 4.
The lamp housing 34 increases the efficiency of the light that is irradiated from the lamp 36 by minimizing light loss. The light guide panel 12 has a fixed tilt angle and guides the light incident from the lamp 36 to the LCD panel 2. The reflection sheet 14 directs the light generated from the lamp 36 to the light guide panel 12 to minimize light loss. The optical sheets 10 causes the inclined incident light from the surface of the light guide panel 12 and the reflection sheet 14 to vertically travel toward the LCD panel 2.
The guide panel 4 is bent in an ‘L’ shape and placed on the upper surfaces of the edges of the support main 16, and it covers the side surfaces of the support main 16. The guide panel 4 has a receiving part for receiving the rear surface of the LCD panel 2 and side walls for guarding the side surfaces of the LCD panel to support the LCD panel 2.
As illustrated in FIG. 2, the case top 6 formed in a square belt shape has a plane part 6a and a side surface part 6b that are orthogonally bent, so as to cover the edges of the LCD panel 2 and the side surfaces of the support main 16.
The support main 16, which is a mold of plastic material, has the side wall surfaces. The inside of the side wall surfaces includes a step portion in which the backlight unit, the guide panel 4 and the LCD panel 2 are stacked together. Also, the one side of the support main 16 to which the backlight unit is inserted is combined with the cover bottom 20.
The cover bottom 20 protects the backlight unit and supports the support main 16. The cover bottom 20 is formed of a metal material to reinforce the hardness of the support main 16 which is formed of a plastic material.
An assembly process of the related art LCD device will be described hereafter. First, the one side of the support main 16 is combined with the cover bottom 20 using screws. And then, the reflection sheet 14 is provided on the front surface of the combined support main 16 and the cover bottom 20, and the lamp housing 34 where the lamp 36 and the light guide panel 12 are combined is inserted into a space which is formed by one side of the support main 16 and the cover bottom 20. The optical sheets 10 are provided on the light guide panel 12. After completion of receiving the backlight unit, the LCD panel 2 in which the polarizing sheets 8 and 18 are adhered onto the upper and lower surfaces thereof is assembled.
Next, the case top 6, which covers the edges of the LCD panel 2 and the side walls of the support main 16, is combined. In the one side of the support main 16 combined with the cover bottom 20, a combining part formed at one side of the cover bottom 20 is combined with a hook combining part formed at one side of the case top 6.
The case top 6 includes its plane part 6a and a plurality of supporters 7 projected in a direction of the LCD panel, as illustrated in FIG. 2. The supporters 7 are in contact with a gate PCB 30 or a data PCB of the LCD panel 2, thereby maintaining a gap between the case top 6 and driver integrated circuits 35 mounted on tape carrier packages 32 (TCP). Further, the supporters 7 are in contact with the gate PCB 30, the guide panel 4 and other parts so as to fix the other parts or to support the parts during the screw placement.
However, the supporters 7 according to the related art are integrated with the case top 6. Accordingly, when the shape of the parts becomes complicated or their design changes are required, the case top 6 should be wholly redesigned and reproduced to accommodate the design changes in the supports 7. Reproducing a new case top requires a new die for casting and other processes, thereby complicating the manufacturing process and increasing the production cost.